Trap-door-operating mechanism.



W. H. MUSSEY.

TRAP DOOR OPERATING MECHANISM.

APPLICATION FILED MAR. I7. 19H.

Patented June 11, 1918.

2 SHEETSSHEET I.

W. H. MUSSEY.

V TRAP DOOR OPERATING MECHANISM.

. 'APPLLCATION man MAR. 11, 1917. V

- 1,269,557. Patented June 11, 1918.

' 2 SHEETSSHEET 2.

I 2 9.3. F 17 as M 3 10 95 26 WILLIAM H. MUSSEY, OF HOLLIS, NEW YORK.

TRAP-DOOR-OPERATING MECHANISM.

Specification of Letters Patent.

Patented June 11, 1918.

Application filed March 17, 1917. Serial No. 155,520.

To all whom it may concern:

Be it known that 1, WILLIAM H. MUsSEY,

a citizen of the United States, and a resident of Hollis, in the county of Queens, State of New York, have invented certain new and useful Improvements in Trap-Door-Operating Mechanism; and I do herebydeclare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention is directed to the provision of an improved form of spring-actuated hinge for use in supporting the trap-door of a vestibule railway passenger car for elevated or grade level platforms. Such a trap-door is mounted by means of hinges upon the end wall of the car and is normally disposed horizontally over the steps in continuation of the floor of the'car so as to, completethe floor of the vestibule and thus permit passengers to walk directly from the car to the elevated or grade level platform. hen desired thedoor may be turned on its hinges to'an upright or vertical. position close to the endwall of the car to permit an unobstructed use 'of the steps. Such trap-doors are usually held in the closed or horizontal position by a latch and are provided with springsto lift them automatically to open position when the latch is released. V p

In my earlier Patent No. 1,202,566 of OctOber 24, 1916, there is disclosed a novel form of hinge for such trap-door involving with the casing comprising two sections so connected that one of such sections, attached to the trap-door, is rotatable relative to the other section attached tothe car end. The spring thus inclosed is arranged to be compressed, onalowering the door to the hori zontal position, by means of a pair of co acting members one fixed in one of the two casing sections and the other guided for axial movement in the othercasing section. as a result of this construction, the axially movable member compresses the spring during a lowering of the trap-door; so that, upon subsequently releasing the latch which holds the trap-door inits horizontal positio'n,i the spring expands, and by returning T" the axially movable member to its normal position causes a rotative movement of the the use of a hollow casing for the spring,

other member and its casing section and thereby swings the attached trap-door up to its open or vertical position. It is apparent that on the upward movement of the trap door the center of gravity thereof approaches closer and closer the vertical plane of the axis of movement; less and less weight of the door, therefore, resisting the lifting effect of the spring as the door swings up more and more from its horizontal position, until, with the door in vertical position, the entire weight is supported on the hinge. Moreover, at the instant the door is started on its upward swing, the single spring must overcome the inertia ofthe door and the starting friction of the various moving parts. It is this single spring which must accommodate itself to the rapidly changing load in the different positions of the door, and in such a way that the door may be suitably stopped when it reaches its vertical position, without slamming heavily against the car end. -According to the construction of this previous pat ent, the co-acting members must be ofsuch design that by their co-action during the expansion of the single spring employed,

this spring exerts a very powerful action at the instant the latch is released and a diminishing actlon as the'doo'r is rapidly turned upward.

The main object of the present invention is to provide certain improvements in this previous construction. One of these improvements involves the use of a plurality of springs arranged to operate in tandem and so designed and co-acting with the other elements t at the counter-balancing eifect of the entire structure follows a curve practically coincident with the curve of the resistance of the trap-door to elevation. This .curve, it is clear, will be a sine curve, since,

as the door is moved upward, the load varies inversely as the sine of the angle between any two successive inclined positions of the door and its horizontal position.

Among other improvements, the present invention provides a combined anti-friction rotative and thrust bearing, to cooperate.

with the spring system peculiar to the present invention; this hearing also serving incidentally to connect and lock the two casingstogether, so as to make of them and their con? tents a counter-balancing hinge whichisa setfcontained unit, and to thus obviate any necessity for depending upon the auxiliary hinge of the trap-door as the means for preventing a separation of the two casing sections.

The invention will be clearly understood from the following description, when taken in connection with the accompanying drawings, of which Figure l is a diagrammatic "iew in elevation of a portion of the end of a railway passenger car; Fig. 2 shows in shown to the left of Fig. 3; Fig. 4 is a section on the line l l of Fig. 3; Fig. 5 is a section on the line 55 of Fig. 3; Fig. 6 is a section on the line 6-45 of Fig. 8; Fig. 7 is an end elevation of the left-hand casing section shown in Fig. 6, and of the member therein; Fig. 8 is a section on the line 88 of Fig. 6; Fig. 9 is a section on the line 99 of Fig. 8; and Figs. 10, 11, 12 and'13 are detail views, Figs. 11 and 12 showing in perspective the co-acting members carried by the casing sections, and Figs.

10 and 13 being respectively end elevations of the members of Figs. 11 and 12.

Referring to these drawings, Fig. 1 shows a portion of the end of the car body 15 and the trap-ddor 17, the latter being shown in its closed position.

As shown best in Fig. 3, the counter-balancing hinge comprises a self-contained unit including a casing section 18, afiixed to the under side of the door 17, and a complementary casing section 19 aflixed to the car end. In order that a single means may interlock the two sections into a single casing for the counter-balancing unit, and at the same time, furnish a combined anti-friction rotat-ive and thrust bearing between the two; casing sections, anannular groove is formed exteriorly of the section 18 and a similar groove is formed interiorly of the section 19, these two grooves forming the ball-race for a ball-bearing 20 when the ends of the two sections are fitted one within another as shown in Figs. 3 and 6.

Within the hollow casing are two coacting members 21 and 22. The member 21 is secured within the casing section 18 so as. to rotate with that section when the (lQOl' is swung up or down. The member 22, while axially movable within its casing section 19, is. restrained against rotation relative thereto by the polygonal. cross-sections of these two parts interfitting as shown in Fig. 5. Fig. 12 shows clearly the portion 22 of the member 22 as being of this poly onal cross-section. Fig. 3 shows this axially movable member 22 at its extreme inner po sitioningits casing sec-tion19, thus tocompress a plurality of springs 23, 24, 25, 26

and 27. It will be observed that the springs 23 and 2 1 when compressed are almost completely housed within a cylindrical recess formed in the portion 22 of the member 22, and the springs 26 and 27 when compressed are similarly housed within a cylindrical recess formed in a plug 29 and axially alined with the similar recess formed in member 22; this plug 29 being threaded in the outer open end of the casing section 19. The intermediatespring 25 is separated from the two terminal groups of springs thus housed, by means of piston disks 30.

While the springs are expanding or being compressed, these piston disks of course move axially of the casing section 19. These disks, however, are always maintained concentric with the springs, by means of the ribs 19 shown in Figs. 3, 4 and 5, and the four straight, inclined walls defining the polygonal cross-section of the casing section 19. This polygonal subdivision of section 19, lies betweenthe points 19* and 19 of Fig. 3. As indicated clearly in Fig. 5, the piston disk to the left of Fig. 3, may slip smoothly from the guidance of ribs 19 to that of these four inclined walls, and vice versa; the other piston disk always keeping to the four ribs. In this connection it 24 and 27 Asshown in Fig. 8, the core 2 1 i i is just a trifle shorter than the solid height of its sprmg 24, and the core 27 is just a trifle shorter than the solid height of its spring 27. These cores may be loose within their springs, but it is preferred to form the core 2 1 integral with the mem ber 22 and the core 27 a integral with the end plug 29.

The member 21 is permanently anchored in the casing section 18. The member is inserted into the section so that a square reduced extension carried by the member may be swaged into a square hole 18 as shown at 21 in Fig. 3. Before the swaging opera tion is commenced, the screws 33 are employed as shown in Figs. 3 and 7, to set the member 21 ready for swaging, so that the casing section 18 may be arranged vertically to rest on the feet or lugs 31 to protect the outer end face of the member 21 against any chance of marring or burring. It will be understood, of course, that with helical ribs fitting within helical slots with some degree of snugness, any marring or barring of the outer end face of the member 21 will so riously interfere with further'assemblyof the device. The provision of the conical recess 21 in the square extension 21 permits the latter to be swaged in place by blows so dia as . outer edge of the latter.

rected that the screws 33 will not be subjected to impracticable shearing strains.

In joining the two casing sections, the coacting members 21 and 22 should be firstinterengaged, and then the sect-ion 18 telescoped within the section 19 to permit the ball-bearing 20 to be formed. Beforethe casing sections may be thus telescoped, ,the section 18 must be arranged relative to the section 19 as indicated in broken lines in Fig. 8, that is, the lugs 34 of section 18 must lie opposite the gapsbetween the two transverse ribs 37' formed inside section 19. Thereupon the lugs are passed through the gaps so as to bring the internal annular groove on the section 19 opposite the external annular groove onthe section 18 to form the ball-race for the ball-bearing 20. A proper number of balls may then be deposited in the ball-race by way of a tapped hole for the screw 38, and the parts finally locked together by inserting such screw.

The hinge thus constructed and assembled is secured to thetrap-door 17 near the The trap-door near its inner edge, as shown in Fig. 3, is provided with an auxiliary hinge comprising .a pintle 89 on the end of a pintle bracket secured to the under side of the trap-door, the pintle turning in a bearing piece 41 riveted to the riser 42 of the top car step.

While the door is being lowered tohorizontal position, the member 22 is caused, to gradually advance to the right toward the location shown in Fig. 3; At the completion of this movement of the member 22 all the springs are compressed to the predetermined limit, which is reached just as the door snaps into en agement with the usual latch (not shown) or holding the door in its horizontal position. The'springs 26 and 27 are together weaker than the combined strength of the springs 23 and 24, which latter are together weaker than the spring 25. Thus, as the door is lowered more and more toward its horizontal position, the resistance to compression of the counter-balancing spring system increases more and more. But as the door is lowered more and more, its center of gravity shifts farther and farther away from the vertical plane of its axis. As

a result, the resistance of the door to'manual lowering is actually inconsiderableand almost unnoticed. On the other hand. upon releasing the latch which holds the door in its horizontal position, the springs operate as follows: first, a powerful initial upward shove isgiven, sufiici'ent to overcome the inertia and starting friction of the horizontally arranged door, and to impart enough momentum thereto to carry the door well on its way toward the vertical position; and then the acceleration drops so as to gradually reduce the momentum in correspondence with the diminishing load. Thedoor is thus given an even movement throughout its whole upswing, although subjected to a powerful shove at the beginning of itsmovement and, finally coming to rest in its verticalposition very gently and without any suggestionof a: slam. Being arranged in tandem, the springs are all compressed to the predetermined maximum at the same instant, that is, when the door reaches its horizontal position. Preferably, all of the springs are compressed solid when the door is thuslowered. a i j Should one of the springs break, the door will nevertheless tend to keep its vertical position, or at leastv will'be prevented from falling, freely from such position. Also, a broken spring will. not jam the counterbalancing hinge so that the door may not be raised to the vertical. [Ofcourse no two springs separated by a piston disk 30 may ever become enmeshed to jam the counterbalancing hinge; and the cores 24 and 2'7 prevent the springs 24 and 27 when broken from becoming enmeshed with. the springs 23 and 26 with which they are grouped. I

These cores 24c fand 27 act also as stops or spacers to absorb the slight shock which accompanies compressionof the springs to the predetermined maximum at the instant when the door reachesits lowered position, and the cores. thereby serve to relieve the members 21'and', 22 from any. undesirable jars and strains 'towhich they might otherwise be subjected.

. The ball-bearing 20 serves at once as an interlock, anti-frictionjournal, and thrust bearing, It interlocks the two casing sections togetherto make the counter-balancing hinge a self-containedunit at all times. As a result, the counter-balancinghinge need not be assembled while beingattached to the car end and trap-door. and after the pintle 39 has been inserted inits bearing piece l1; and thehinge' may be removed at any time without first havingto take the same apart. The ballbearing 20 serves also as an antifriction journal tofacilitate the orderly compression and: expansion of the springs as predetermined, and ,to permit the members 21 and 22 to intcrfit with a less degree of snugness than would otherwise be required. The ball-bearing 20serv'es further .as a thrust'bearing, and thereby avoids putting any thrust pressure on the trap-door to be taken up by the bearing piece 41 of the auxiliary hinge. I To thlsend the lugs 3410f thememberlS cooperate with the ribs 37 of the member 19 to give the thrust bearing the requisite strength, and at the same time to afford asimple aud convenient means for permittingthe memberlS to be telescoped within tllel llQDlbBlflQ before they are interlocked. In this connection, it ispointed out that thesevlugsfial arethe'same lugs which were useful in' ipermitting the square extenits sion 21 to be swaged into place without injuring the member 21.

I claim:

1. A counter-balancing means for a trapdoor hinged to swing on a horizontal axis eccentrically disposed relative to the center of gravity of the door, comprising, in combination, a hinge member secured to a fixed portion of the car, a complementary hinge member secured to the door, and a plurality of springs operatively associated with the two members, the springs being so relatively tensioned that when the door is released in its horizontal position first both and then one only of said springs will act on the door to lift it toward its horizontal position.

2. In a counter-balancing means for a trap-door of the kind described, in combination, a hinge member secured to a fixed portion of the car, a complementary hinge member secured to the door, a part fixedly carried by one of the members, a part movably carried by the other member and adapted to move relatively to the first-mentioned member as the door is lo'wered toward vertical position, and a plurality of springs of different strengths arranged in tandem to be compressed during said relative movement between said two parts.

3. In a counter-balancing means for a trap-door hinged to swing on a horizontal axis eccentrically disposed relative to the center of gravity of the door, in combination, a hinge member secured to a fixed portion of the car, a complementary hinge member secured to the door, spring-compressing means carried partially by one of said members and partially by the other, and spring means compressed by the spring-compressing means as the door is swung from its vertical to its horizontal position, the spring means being so designed that as the door is lowered and its center of gravity moves farther and farther away from the vertical plane passing through the doors axis the resistance to compression of the spring means correspondingly increases. 7

4:. In a counter-balancing means for a trap-door hinged to swing on a horizontal axis eccentrically disposed relative to the center of gravity of the door, in combination, a hinge member secured to a fixed portion of the car, a complementary hinge member secured to the door, spring-compressing means carried partially by one of said members and partially by the other, a plurality of springs of diflerent strengths to be compressed by the spring-compressing means when the door is in its horizontal position, the parts being so designed that when the door is released from its horizontal position the various springs act to first move the door upward with a force sufficient to overcome its inertia and starting frictionand then continue the movement" while diminishing the force in correspondence with the diminishing load as the doors center of gravity approaches closer and closer the vertical plane passing through its axis.

5. In a counter-balancing means for a trap-door of the kind described, the combination with the two-section casing and the co-acting relatively rotatable members arranged therein so that one of these members establishes a spring recess within one of the sections the length of which recess is to be shortened by the movement of one of said members when the door is being lowered to horizontal position, of a spring system confined in the recess and comprising a plurality of springs of different strengths which are simultaneously variously compressed as the length of the recess is shortened.

6. A counter-balancing means for a trapdoor of the kind described, comprising, in combination, a hinge mounting therefor, and a spring means associated with such mounting for being compressed when the door is lowered to its horizontal position and for moving the door from its horizontal to its vertical position, the hinge mounting including two relatively movable hinge members one of which partially telescopes within the other, and an interlocking means for the two sections including a ball-bearing the ballrace of which is partially carried by one of the hinge members and partially by the other.

7. A counter-balancing means for a trapdoor of the kind described, comprising, in

combination, a hinge mounting therefor, and

a spring means associated with such mounting for belng compressed when the door 18 lowered to lts horizontal position and for moving the door from its horizontal to its vertical position, the hinge mounting including two relatively movable hinge members one of which partially telescopes within the other, and an interlocking means for the two sections including a ball-bearing the ball race of which is partially carried by one of the hinge members and partially by the other, one of the members providing a recess for confining the spring means and the other member having associated therewith and operated thereby a plunger for compressingthe spring means when the door is lowered to horizontal position, whereby the ballbearing interlock acts also as a combined anti-friction rotative and thrust-bearing be tween the two hinge members. I

8. In a trap-door of the kind described, a hinge having a tubular part, a complementary hinge member, a ball-bearing including an annular ball race for operatively connecting the two hinge members, and a counterbalancing means operating within said tubular part.

9. In a counter-balancing means for a trap-door of the kind described, the combination with the two-section casing and the co-acting relatively rotatable members arranged therein so that one of these members establishes a spring recess within one of the sections the length of which recess is to be shortened by the movement of one of said members when the door is being lowered to horizontal position, of a spring system confined in the recess and comprising a plural- 10 ity of helical springs of different strengths arranged in line to be simultaneously compressed as the length of the recess is shortened, a plurality of spacer disks for the springs, and a plurality of spacer cores sleeved by the springs, each spacer core bein approximately as long as the solid height 0 the spring which sleeves it.

In testimony whereof I afiix my signature.

WILLIAM H. MUSSEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, ,Washington, D. 0. 

